165819953 has 8 divisors (see below), whose sum is σ = 178779048. Its totient is φ = 152889984.

The previous prime is 165819947. The next prime is 165819959. The reversal of 165819953 is 359918561.

It is an interprime number because it is at equal distance from previous prime (165819947) and next prime (165819959).

It can be written as a sum of positive squares in 4 ways, for example, as 33500944 + 132319009 = 5788^2 + 11503^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 165819953 - 2⁸ = 165819697 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 165819898 and 165819907.

It is not an unprimeable number, because it can be changed into a prime (165819959) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5375 + ... + 18987.

It is an arithmetic number, because the mean of its divisors is an integer number (22347381).

Almost surely, 2^165819953 is an apocalyptic number.

165819953 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

It is an amenable number.

165819953 is a deficient number, since it is larger than the sum of its proper divisors (12959095).

165819953 is a wasteful number, since it uses less digits than its factorization.

165819953 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14563.

The product of its digits is 291600, while the sum is 47.

The square root of 165819953 is about 12877.1096524026. The cubic root of 165819953 is about 549.3876965498.

The spelling of 165819953 in words is "one hundred sixty-five million, eight hundred nineteen thousand, nine hundred fifty-three".